Electric water heater



Nav. 17 1925. l

A. M. DUFFIE maca-mc uuu-an nam-sn Filed Julne 5. 1923 Inventor HnenMq/W'a. r @JP itat:if: 55.1.3.1..

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trarne Patented Nov. 17, 1925.

UNITE FME.

ALLEN IVI. DUFFE, CIF BUFFALQ, NEVJ YRK, LSSIG'NOR TO TLLIAM H. ROBNSON,

OE BFFAL, NEVI' YORK.

ELECTRIC 'WATER Application led une 5, 13H3.

To all whom t may concern.'

Re it known that l? ALLEN M. Dorm c, a citizen ot the United States7 residing at Butlalo, in the county oit Erie and State ot New York, have invented. a new and uset'ul improvement in Electric "Water Heaters, of which the following is a specitication.

This invention relates to improvement-s in electric water heaters, proposing a heater which is especially intended for use in connection with a domestic storage tank such as the usual boiler' ot a furnace or range.

The principal objects of the invention are tc provide an electrical heater which will operate with high etliciency and with low current consumption, which will not be liable to derangemcnt, and in which the heating element is readily accessible as occasion may require.

`With t-he above objects in view, the heater is so constructed that the flowing stream is definitely divided into several rapidly moving convection currents each subject to the heat developed throughout the iull extent ot the heating element whereby the water is rapidly heated to a high degree and a rapid circulation between the heater and the storage tank is effected; the heater is also so constructed that loss et heat by absorption is reduced to a minimum and that the fullest benefits ot radiation and ot the conductivity of the tubes Jjor the convection currents are obtained; the heater is also so constructed that the heating ele-ment is thoroughly protected against contact with metallic parts, and together with the parts by which it is supported is readily removable and replaceable as a unit with reference to the other parts ot the heater structure.

rlhe invention consists generally in certain novel features ot' structure combination and organization which will be set 'forth in detail as the description proceeds.

An embodiment of the invention is illustrated in the accompanying drawing wherein;

Figure 1 is a vertical sectional view ot the heater.

Figure :2 is a plan view.

Figure 3 is a horizontal section view on the line 3 3 of Figure 1.

Figure -i is a detail elevation ot the lower portion of the support tor the heating element.

Serial No. 643,560.

Tater is conducted from the storage tank (not shown) to the heater by a pipe 5 and is returned from the heater to the storage tank by a pipe 6. The heater is characterized by a plurality `of convolute conductors 7, preferably of copper, which extend between and are supported by the pipes 5 and 6, the conductors 't' being each ot' small diameter as compared with the diameter ci the pipes 5 and 6 and being helically wound with their convolutions lying in close adjacency whereby to provide a cylindrical structure through which the separate streams of water flow spirally, the pitch of the convclutions being selected to provide tor the maximum heating surface and e3:- tent of travel of the water with reference to the length oit the heater. The tubes 7 may be provided in any desired number. As shown and preferred, three of such tubes are used. The cylinder composed of the tubes surrounds a heat-ing element 8 and is in turn surrounded by a cylindrical reliector 9, the inner tace of which is highly polished. Each tube is thus subject throughout its extent to the heat radiated by the element S and reflected by the cylinder 9. The heating element 8 preferably consists of coiled nichrome wire bent into parallel convolutions each extending substantially the full length ot the cylinder provided by the tubes 7, the number of convolutions being a matter ot choice and being determined in accordance with the requirements of the heater. As shown eight of such convolutions are provided.

'lhe cylinder 9 is secured as by bolt and nutfastenings (not shown) to an outer supporting shell 11 which may be attached to any stationary supportg'and the space between the cylinder 9 and the shell 11 is iilled with a cylinder lZ'ot heat insulating material such as compressed asbestos packing. The cylinder 9 delimits a heating chamber which is completely enclosed, its closure being completed by a bottom head 13 and a top head 14. The heads 13 and 14 are formed to fit trictionally and securely within the ends ot the shell 11 and are provided with handles 15 for their ready removal from said shell and with recesses 16 which altords clearances for the pipes 5 and 6 respectively. The heads 1S and let4 are provided in their inner sides with niet-al the post similarly to the sleeves 23.

plates having highly polished surfaces for the purpose of retiection and beyond said plates are provided with layers of compressed heat insulating material.

rlhe element 8 is preferably supported from the cylinder 9 by means of a bridge bar 17, the ends of which are removably fitted in recesses 1S open to the upper edge ot said cylinder. The bridge bar 17 'supe ports by means ot a nut 17 1 a centrally arranged hanger post 2O upon which are mounted at suitable intervals rigid plates 21 of compressedber or other suitable insulating material, these plates having openings 22 through which the convolutions ot thc element 8 extend, thereby serving positively to hold these convolutions spaced troni one another. The plates 21 areniutually spaced and supported by spacer sleeves 2?) litted on the post'20. litt the loiver end ot the post 20, a plate 2d is supported by means ot a nut'25. The plate 211. is arranged below the loivermost plate 21 and the latter is supported by a` spacer sleeve '23L Fitted on The plate 24 is ot insulating material similar to the plates 21fandis provided ivith'binding posts 26 which serve tor the connection ot the terminals ot the'element S and ot the line Wires, these, suitably insulated, being extended through an opening 27 4in ythe cyn lindrical Wall ot the 'heater near Aits lower end. The uppermost plate 21 is arranged at a'suitable distance below the bar 17 from which it is spaced by a sleeve 23b mounted on the post 'and the convolutions ot the elementsS areconnected by poi ions which are threaded through the openings 22 ot the uppermost and loiverniost plates'21.

It Will be seen that the heating element and its supporting parts are assembled as a self-contained unit, wherein the post 2O With the cooperation ot the nuts 17 and provides. a mounting lfor all ot the remaining supportingparts and these in turn carry the element 8 and positively 'mainn tain the proper spacing ot the convolutions thereot trom one another and from thc'tubes 7. rlhe removal of the heating element is etlected by removing the heads il'a'nd 14;, disconnecting the line Wires trein the terminals 26 and by means-ot the bridge bar 17 lifting the unitary structure trom the heating' chamber.

The conductors 7 divide the Water which passes through the heater into separatey convection streams ot small volume, which streams flow through a common heating chamber, wherein each stream is subject to heat developed by the element '8 throughout the full extent thereof and transmitted byr direct or retiected radiation tothe highly conductive conduit by Which the streams are confined and directed. ln this Way'it is possible lo heat. volume o'twater su'iicient for normal domestic uses in a comparatively short time to a suitably high degree with a minimum consumption ot electric current.

Having fully described my invention, I claim:

1. ln an electric water heater, in combination, a cylinder delimiting a heating chamber closed at its ends, an inlet pipe and an out-let pipe arranged at the opposite ends ot said heater, a plurality ot tubes connected to said pipes and having convolutions lying closely adjacent one aneth-er and arranged to 'torni a cylinder which is litted Within said cylinder lirst named, said tubes being each ot small diameter as compared with said pipes, and an electrical heating element arranged Within 'the cylinder .termed by said tubes.

2. ln an electric water heater, in combination, a cylinder dclimiting a heating chamber closed at its ends, said cylinder having an internal reiiecting surface, an inlet pipe and an outlet pipe arranged at the opposite ends oit said heat-er, a Aplurality ot tubes connected Ito said pipes and having convolutions llying closely adjacent one another and arranged to torni a cylinder which is iitted Within said cylinder lirst named, said tubes'being each of small diameter as compared with said pipes, and an electrical heating element arranged ivi'thinthe cylinder 'formed by said tubesy 3. In an elect-ric Water heater, in combination, a cylinder delimiting a heating chamber closed at its ends, an inlet pipe and an outlet pipe arranged at 4the opposite ends of said'heater, a water conducting medium connectedto said pipes andhaving the form of a cylinder fitted Within ysaid cylinder first named, an electrical heating element arrangedwithin the cylinder'tormed by said conducting medium, and support` ing means for said heating element including a bridgebar removably supported at the uppe'rend oft said heating chamber and from 'which said heating element and the other supporting parts tli'eretor are suspended.

4:. In an electric Water heater, in combination, a cylinder delimiting a heating chamber Vhaving a removable end closure, an inlet'pipe and an outlet 'pipe arranged at the opposite ends of 'said heater, a Water conducting medium connected to said pipes and `having 'the 'form ot a cylinder iitted Within said cylinder iirst named, an electrical heating element arranged lWithin the cylinder formed by said conducting medium, and a support for said heating element, said support and said heating element being Organized as a unit removabl'etrom 'said heating lchamber upon the removal of said end head.

5. In an electric Water heater, in combination, a. cylinder delimiting a heating chamber having a removable end closure, an inlet pipe and an outlet pipe arranged at the opposite ends of said heater, a Water conducting medium connected to said pipes and having the. form ot a cylinder litted Within said cylinder lirst named, an electrical heating element arranged Within the cylinder formed by said conducting medium7 and supporting means for said heating element comprising a bridge bar removably supported at the upper end of said heating chamber, a central post pendent from and supported by Isaid bridge bai',.and insulating plates arranged at regular intervals on said postand having openings through which the convolutions oli tend.

G. In an electric Water heater, .in con1hination, a cylinder delimiting a heating chamber closed at its ends7 an inlet pipe and an outlet pipe arranged at the oppositel ends or' said heater, a Water conducting inedium connect-ed to said pip-es and having the torni of a cylinder htted within said cylinder lirst named, an electrical heating elew ment arranged Within the cylinder lormed 'said heatingl element c by said conducting medium, and 'supporting means for said heating element including a bridge bar removably supported upon the upper end or' said cylinder first named and from Which said heating element and 'the other 'supporting parts therefor are suspended.

7. In an electric Water heater, in combination, a cylinder delimiting a heating chamber having a removable end closure, an inlet pipe and an outlet pipe arranged at the opposite ends of said heater, a Water conducting medium connected to said pipes and having the form of a cylinder fitted Within said cylinder :lirst named, an electriF cal heating element arranged Within the cylinder formed by 'said conducting medium, and a support for said heating element, said support and said heating element being organized as a unit removable from said heating chamber upon the removal oi said end head and said support including a part which has supporting engagement upon the upper end or' said cylinder irst named.

ln testimony whereof I aiiiX my signature.

ALLEN M. DUFFIE. 

